US5645836A - Anti-AIDS immunotoxins - Google Patents

Anti-AIDS immunotoxins Download PDF

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US5645836A
US5645836A US08/422,578 US42257895A US5645836A US 5645836 A US5645836 A US 5645836A US 42257895 A US42257895 A US 42257895A US 5645836 A US5645836 A US 5645836A
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immunotoxin
hiv
reverse transcriptase
cells
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George Barrie Kitto
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Research Development Foundation
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Priority to US08/422,578 priority Critical patent/US5645836A/en
Priority to ZA9602911A priority patent/ZA962911B/xx
Priority to CA002216210A priority patent/CA2216210A1/en
Priority to PCT/US1996/004996 priority patent/WO1996032416A1/en
Priority to IL11787096A priority patent/IL117870A/en
Priority to EP96912684A priority patent/EP0820470A4/en
Priority to AU55413/96A priority patent/AU697418B2/en
Priority to JP8531175A priority patent/JPH11503730A/ja
Priority to NZ306768A priority patent/NZ306768A/en
Priority to RU97118664/13A priority patent/RU2191596C2/ru
Priority to CNB961939818A priority patent/CN1154659C/zh
Priority to KR1019970707271A priority patent/KR100457992B1/ko
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Priority to US09/109,154 priority patent/USRE36866E/en
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/08—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from viruses
    • C07K16/10—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from viruses from RNA viruses
    • C07K16/1036—Retroviridae, e.g. leukemia viruses
    • C07K16/1045—Lentiviridae, e.g. HIV, FIV, SIV
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/40—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against enzymes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/395—Antibodies; Immunoglobulins; Immune serum, e.g. antilymphocytic serum
    • A61K39/42—Antibodies; Immunoglobulins; Immune serum, e.g. antilymphocytic serum viral
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/68—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment
    • A61K47/6801—Drug-antibody or immunoglobulin conjugates defined by the pharmacologically or therapeutically active agent
    • A61K47/6803—Drugs conjugated to an antibody or immunoglobulin, e.g. cisplatin-antibody conjugates
    • A61K47/6811—Drugs conjugated to an antibody or immunoglobulin, e.g. cisplatin-antibody conjugates the drug being a protein or peptide, e.g. transferrin or bleomycin
    • A61K47/6817—Toxins
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/68—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment
    • A61K47/6835—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment the modifying agent being an antibody or an immunoglobulin bearing at least one antigen-binding site
    • A61K47/6839—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment the modifying agent being an antibody or an immunoglobulin bearing at least one antigen-binding site the antibody targeting material from viruses
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/12—Antivirals
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/12—Antivirals
    • A61P31/14—Antivirals for RNA viruses
    • A61P31/18—Antivirals for RNA viruses for HIV
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/08—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from viruses
    • C07K16/10—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from viruses from RNA viruses
    • C07K16/1036—Retroviridae, e.g. leukemia viruses
    • C07K16/1045—Lentiviridae, e.g. HIV, FIV, SIV
    • C07K16/1072—Regulatory proteins, e.g. tat, rev, vpt
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/46—Hybrid immunoglobulins
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/505—Medicinal preparations containing antigens or antibodies comprising antibodies
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00—Medicinal preparations containing peptides

Definitions

  • the present invention relates generally to the fields of molecular immunology and therapies for the Acquired Immune Deficiency Syndrome (AIDS). More specifically, the present invention relates to novel immunotoxins for the treatment of AIDS.
  • AIDS Acquired Immune Deficiency Syndrome
  • AZT AZT is not effective for a long period of time. This treatment is also extremely expensive and has several accompanying side effects such as nausea, seizures, liver function abnormalities, and bone marrow suppression. Other chemical variants of AZT, such as DDC and DDI, show promise in clinical trials but are, however, of limited effectiveness. Although a number of other drugs and treatment regimes are being investigated, there is clearly a pressing need for additional drugs and new approaches to treating this disease.
  • Immunotoxin therapy has, however, proven very effective against several other diseases when there is an absolutely specific target for the antibody portion of the antibody-toxin conjugates.
  • the Pseudomonas exotoxin was coupled to a monoclonal antibody targeted against ovarian cancer tumors. It effectively inhibited the growth of human ovarian cancer cells in a mouse model (Willingham, M. C., et al., 1987). What is needed for AIDS immunotherapy is a highly specific and unvarying target.
  • the HIV enzyme reverse transcriptase is of absolutely critical importance for viral replication.
  • the enzyme plays an essential role in catalyzing the formation of a DNA copy of the viral genetic material (RNA).
  • RNA viral genetic material
  • the DNA is then used either for generating more copies of the virus immediately or for integration into the patient's genome, for later expression of the disease.
  • This critical role of reverse transcriptase is likely the reason for its highly conserved structure.
  • copies of the reverse transcriptase or portions thereof are attached to the exterior cell surface. The cell surface expression of the reverse transcriptase is markedly greater than that for even the viral envelope proteins.
  • the prior art is deficient in the lack of effective means of therapeutically treating the acquired immune deficiency syndrome.
  • the present invention fulfills this longstanding need and desire in the art.
  • composition of matter comprising an immunotoxin, said immunotoxin comprising a toxin chemically conjugated to a monoclonal antibody directed against viral reverse transcriptase.
  • a pharmaceutical composition comprising an immunotoxin, said immunotoxin comprising a toxin chemically conjugated to a monoclonal antibody directed against viral reverse transcriptase and a pharmaceutically acceptable carrier.
  • a method of treating the Acquired Immune Deficiency Syndrome comprising the step of administering to a human having said syndrome a pharmacologically effective dose of the novel composition of the present invention.
  • a method of treating an individual infected with the Human Immunodeficiency Virus comprising the step of administering to said individual a pharmacologically effective dose of the novel composition of the present invention.
  • FIG. 1 shows the general immunotoxin synthetic scheme (FIGS. 1A, 1B, 1C, 1D)
  • FIG. 2 shows the transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin directed against an HIV strain (HIV-AC-1) infecting H9 cells with exposure of the cells to the immunotoxin for either 24 or 48 hours.
  • FIG. 3 shows the effects of the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin on the HIV cell line H-9 and HIV strain, PM-213 after exposure of the cells to the immunotoxin for either 24, 48 or 72 hours.
  • FIG. 4 shows a dose response relationship for cytotoxicity for the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin construct of the present invention after 1 day of incubation.
  • FIG. 5 illustrates a dose response relationship for cytotoxicity for the anti-reverse transcriptase monoclonal antibody-gelonin immunotoxin of the present invention.
  • FIG. 6 shows the effect of the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin on H9 cells +HIV-IIIB.
  • FIG. 7 shows the effect of treating H9+MN cells for 3 days with the anti-reverse transcriptase monoclonal antibody-pokeweed antiviral protein immunotoxin of the present invention.
  • FIG. 8 illustrates the effect of the gelonin immunotoxin of the present invention on H9 cells plus HIV-IIIB over 3 days of incubation.
  • FIG. 9 illustrates the effect of the gelonin immunotoxin of the present invention on H9 cells plus HIV-MN.
  • This present invention discloses the development of a new approach to immunotoxin therapy of the Acquired Immune Deficiency Syndrome (AIDS).
  • the design of the therapeutic pathway is based on delivery of extremely potent toxins specifically to cells infected with the AIDS virus, by targetting the infected cells using monoclonal antibodies directed against the viral reverse transcriptase.
  • HIV infected cells express the viral reverse transcriptase on the cell surface.
  • the HIV reverse transcriptase varies in structure very little from strain to strain and from isolate to isolate. This is unlike most of the HIV viral proteins, which are exceptionally variable.
  • the present invention discloses immunotoxins prepared using different monoclonal antibodies against the HIV-1 reverse transcriptase and a variety of both single and double chain, catalytic ribosome inactivating toxins, including poke-weed antiviral protein, gelonin ricin A chain, modeccin and dodecandrin.
  • an immunotoxin is a function of both antibody and toxin. Factors governing cell binding, internalization, translocation from surface to interior and overall cytotoxicity are complicated and often unpredictable. It is very difficult, therefore, to determine which monoclonal antibody should be conjugated to a specific toxin.
  • the present invention establishes optimal dose response curves for the MAb-PAP (Pokeweed antiviral protein) and MAb-Gelonin immunoconjugates. These dose response curves facilitate comparison with other types of immunoconjugate preparations.
  • the present invention also discloses preparation of immunoconjugates, prepared with the same monoclonal antibody, but containing the toxins ricin, ricin A chain, and dodecandrin, for their cytotoxic potential against HIV-infected cells.
  • the present invention discloses additional monoclonal antibodies against HIV-1-reverse transcriptase. These monoclonals are then each coupled to PAP (Pokeweed antiviral protein), gelonin, ricin, ricin-A chain or dodecandrin and subjected to cytotoxicity testing.
  • PAP Pokeweed antiviral protein
  • the present invention describes a composition of matter, comprising an immunotoxin, said immunotoxin comprising a toxin chemically conjugated to a monoclonal antibody directed against viral reverse transcriptase.
  • a panel of more than 70 mouse monoclonal antibodies have been prepared against HIV-1 reverse transcriptase. These differ in IgG and IgM classes and subtype.
  • Representative examples of monoclonal antibodies specific for HIV reverse transcriptase include: HIVRT 10-1-a, HIVRT 2-2-F8, HIVRT 11-1-b, HIVRT 6-1-a, HIVRT 12-1-c, HIVRT 6-9, HIVRT 15-3, HIVRT 16-4, HIVRT 14-1-d, HIVRT 18-1, HIVRT 2-3-b, HIVRT 10-1-b and HIVRT 10-4.
  • the present invention also provides a method of treating the Acquired Immune Deficiency Syndrome comprising the step of administering to a human having said syndrome a pharmacologically effective dose of the composition of claim 4.
  • the present invention provides a method of treating an individual infected with the Human Immunodeficiency Virus comprising the step of administering to said individual a pharmacologically effective dose of the composition of the present invention.
  • compositions may be prepared using the novel immunotoxins of the present invention.
  • the pharmaceutical composition comprises the novel immunotoxins of the present invention and a pharmaceutically acceptable carrier.
  • a person having ordinary skill in this art would readily be able to determine, without undue experimentation, the appropriate dosages and routes of administration of the different immunotoxins disclosed by the present invention.
  • a pharmaceutical composition comprising the novel immunotoxins of the present invention and a pharmaceutically acceptable carrier is also provided.
  • the pharmaceutical compositions of the present invention are suitable for use in a variety of drug delivery systems.
  • Methods for preparing administrable compounds will be known or apparent to those skilled in the art and are described in more detail, for example, in Remington's Pharmaceutical Science, 17th ed., Mack Publishing Company, Easton, Pa. (1988).
  • the immunotoxins of the present invention may be administered to a patient either singly or in a cocktail containing two or more immunotoxins, other therapeutic agents, compositions, or the like, including, but not limited to, immunosuppresive agents, tolerance-inducing agents, potentiators and side-effect relieving agents.
  • immunosuppressive agents useful in suppressing allergic reactions in a host.
  • Preferred immunosuppressive agents include prednisone, prednisolone, DECADRON, cyclophosphamide, cyclosporine, methotrexate and azathiprine.
  • Preferred potentiators include monensin, ammonium chloride, perhexiline, verapamil and amantadine.
  • the immunotoxins of the present invention may be administered after formulation into an injectable preparation.
  • Parenteral formulations are known and are suitable for use in the invention, e.g., intramuscular or intravenous administration.
  • the formulations containing therapeutically effective amounts of immunotoxins are either sterile liquid solutions, liquid suspensions or lyophilized versions, and optimally contain stabilizers and excipients.
  • Lyophilized compositions are reconstituted with suitable diluents, e.g., water for injection, saline, 0.3% glycine and the like, at a level of about from 0.01 mg/kg of host body weight to 10 mg/kg where the biological activity is less than or equal to 20 ng/ml when measured in a reticulocyte lysate assay.
  • the pharmaceutical compositions containing immunotoxins of the present invention is in a range of from about 0.01 mg/kg to about 5 mg/kg body weight of the patient administered over several days to about two weeks by daily intravenous infusion.
  • concentration to be used in the vehicle is subject to modest experimental manipulation in order to optimize the therapeutic response.
  • the immunotoxins of the present invention may be administered by aerosol to achieve localized delivery to the lungs. This is accomplished by preparing an aqueous aerosol, liposomal preparation or solid particles containing immunotoxin. Ordinarily, an aqueous aerosol is made by formulating an aqueous solution or suspension of immunotoxin together with conventional carriers and stabilizers.
  • the carriers and stabilizers vary depending upon the requirements for the particular immunotoxin, but typically include: nonionic surfactants, innocuous proteins, e.g., albumin, sorbitan esters, lecithin, amino acids, e.g., glycine, and buffers, salts, sugars or sugar alcohols.
  • immunotoxins of the present invention may be administered orally by delivery systems such as proteinoid encapulation as described by Steiner, et al., U.S. Pat. No. 4,925,673.
  • a therapeutically effective oral dose of an immunotoxin of the present invention is in the range of about 0.01 mg/kg body weight to about 50 mg/kg body weight per day.
  • a preferred effective dose is in the range from about 0.05 mg/kg body weight to about 5 mg/kg body weight per day.
  • Th imunnotoxins of the present invention may be adminstered in solution.
  • the pH of the solution should be in the range of pH 5 to 9.5, preferably pH 6.5 to 7.5.
  • the immunotoxin or derivatives thereof should be in a solution having a suitable pharmaceutically-acceptable buffer such as phosphate, Tris(hydroxymethyl)aminomethane HCl or citrate or the like. Buffer concentrations should be in the range of 1 to 100 mM.
  • the immunotoxin solution may also contain a salt, such as sodium chloride in a concentration of 50-150 mM.
  • An effective amount of a stabilizing agent such as albumin, a globulin, a gelatin, a protamine or a salt of protamine may also be included.
  • the present invention also provides a method of treating the Acquired Immune Deficiency Syndrome (AIDS) disease in a human comprising the step of administering to a human a pharmacologically effective dose of an immunotoxin of the present invention designed to inhibit the replication of the HIV virus.
  • AIDS Acquired Immune Deficiency Syndrome
  • Each of the toxins envisioned for use as part of the immunotoxins can be purified by standard published procedures.
  • the procedures used to purify the ribosome inactivating proteins from extracts are similar for all these proteins.
  • the proteins are predominantly basic in charge and do not bind to anion exchange resins such as DEAE- cellulose.
  • Typical methodologies for poke-weed antiviral protein are given in: Irvin, J. D., Arch. Biochem. Biophys. 169, 522-528 (1975); Irvin, et al., Arch. Biochem. Biophys., 200, 418-425 (1980); Barbieri, et al., Biochem. J., 203, 55-59 (1982);
  • For gelonin, methods are given in : Lambert, J.
  • HIV-reverse transcriptase can be prepared according to the method of Kohlstaedt and Steitz, Proc. Natl. Acad. Sci., 89:1259 (1989).
  • the purification scheme used to prepare HIV-reverse transcriptase utilizes an reverse transcriptase expression clone described by Summers and D'Aquila (1989) and was obtained through the AIDS Research and Reference Reagent Program, Division of AIDS, NIAID, NIH: Reagent Number pKRT2, Catalog Number 393, contributed by Dr. Richard D'Aquila and Dr. William C. Summers.
  • a typical protocol for the production of hybridoma cell lines was as follows. Two male (RTI and RTII) and two female (RTIII and RTIV) six week old balb/c mice were pre-bled for a negative control, and then each was injected with 10 micrograms of recombinant HIV-1 reverse transcriptase. The purity of this protein was checked on an SDS gel. Each mouse was boosted with reverse transcriptase 3 times at 2 micrograms/boost. A sample bleed from each mouse was then extracted and found to have titers ranging from 60,000 to 80,000 (see below for methodology). The two female mice were sacrificed and their spleens were removed.
  • the cells extracted from the immunized spleens were fused with mouse myeloma cells. These fused cells were grown on selective media (1 ⁇ HAT) which does not allow the growth of myeloma fused myeloma cells. This media contains hypoxanthine, aminopterin, and thymidine.
  • the myeloma fused spleen cells are referred to as hybridomas.
  • Each parent hybridoma was tested using the ELISA method (see below for Indirect ELISA). The hybridomas that tested positive were assayed a second time.
  • the reverse transcriptase antigen was diluted so that each well on a flat-bottomed 96-well microtiter plate (NUNC-Immunoplate, Thomas Scientific) contained 50 nanograms of antigen.
  • the antigen was incubated for 1 hr at room temperature. After incubation, the antigen was shaken out, and the wells were blocked with 100 ⁇ l blocking buffer/well (0.1M potassium phosphate 0.5% Tween 20, 1% bovine serum albumin, pH 7.0) at room temperature for 30 minutes. The plate was washed three times (washing buffer--0.1M potassium phosphate, 0.5% Tween, pH 7.0), and the diluted serum samples were added and incubated overnight at 4° C.
  • the range of dilution was 1:250 to 1:80,000.
  • substrate solution 0.7 mg/ml of 2,2'-amino-bis [3-ethylbenz-thiazoline-6-sulfonic- acid] diammonium salt [ABTS]
  • the screening procedure for detecting positive hybridomas by assay of cell supernatants followed the same protocol as that of the indirect ELISA.
  • Cell supernatant samples were diluted 1:1 with 100 microliters of washing buffer (0.1M potassium phosphate, 0.05% Tween-20, 1 mg/ml bovine serum albumin, pH 7).
  • the antigen used was purified reverse transcriptase and 50 nanograms were dispensed per well. All positives from the first subclone were re-tested, and if they gave positive results again, they were subcloned a second time. The second subclones were also tested using the ELISA method. Once a second subclone tested positive twice, it was expanded and frozen for later use in the production of the monoclonal antibodies.
  • mice Six week old female balb/c mice were used for the production of ascites fluid. They were primed for production by first injecting with pristane. Twelve mice were injected with the hybridoma HIVRT-10-1-a. After 10 days, a noticeable swelling occurred in the peritoneal cavity of the mice. This indicated the presence of a soft, fluid-filled tumor which could be drained using a 201/2 gauge Precision Glide needle to remove the ascites fluid. The needle was inserted into the peritoneal cavity near the upper part of the leg. Each day the puncture point was altered to alleviate as much discomfort as possible. The amount of ascites collected per mouse ranged from ⁇ 0.2 ml to 3.0 ml.
  • the ascites fluid collected on the same day from the same group of mice was combined.
  • the ascites fluid was then centrifuged in a Sorvall Superspeed RC2-B Centrifuge in a Sorvall GSA rotor at 3000 g in sterilized, prebalanced 15 ml tubes for 15 minutes.
  • the fat layer was removed from the top, and the ascites fluid was separated from the cellular debris pellet at the bottom.
  • the collection was terminated when the soft, fluid-filled tumor became hard, and ascitic fluid was no longer draining from the cavity. At this point the mice were killed.
  • the ascites fluid from the each hybridoma line was then combined.
  • the ascites fluid was stored at 4° C. in a sterilized tube.
  • Synthesis of the immunotoxins is carried out by the general procedural steps of: (1) Coupling of Toxin to Linker (FIG. 1A); (2) Coupling of Monoclonal Antibody to Linker (FIG. 1B); (3) Reduction of Toxin+Linker (FIG. 1C); and (4) Linkage of Toxin and Monoclonal Antibody (FIG. 1D).
  • the typical chemistry employed is illustrated in FIG. 1.
  • Each of the above-described steps must be carried out with high yield and with purification of the products if the overall synthesis is to be satisfactorily achieved.
  • the plant toxins were linked to monoclonal antibodies by a disulfide bond with N-succinimidyl 3-(2-pyridyldithio)-propionate (SPDP), to give an average ratio of toxin to antibody within the range 1-2:1.
  • SPDP N-succinimidyl 3-(2-pyridyldithio)-propionate
  • PDP-PAP was prepared by reacting 0.16 mM PAP with 0.48 mM SPDP in a final volume of 0.200 ml buffered with 40 mM sodium phosphate, pH 7.0. After incubation for one hour at 37° C., the mixture was separated on a HPLC Protein Pak 300SW equilibrated with 50 mM potassium phosphate, pH 6.0. Fraction volumes of 1 ml were collected for 25 minutes. Peak fractions were concentrated with the Speedvac. A portion of this PDP-PAP concentrated fraction was run on gel electrophoresis to test for purity.
  • Monoclonal antibodies were incubated with a three fold molar excess of SPDP for 1 hour at 37° C. in 40 mM sodium phosphate, pH 7.0. The sample was then fractionated through a size exclusion HPLC column equilibrated with 50 mM potassium phosphate, pH 6.0. Twenty-five 1 ml fractions were collected for a time of 25 minutes. The peak fractions were concentrated using the Speedvac. A small sample of PDP-MAb was run on SDS gel electrophoresis to check for purity.
  • Monoclonal antibodies were incubated with a three fold molar excess of SPDP for 1 hour at 37° C. in 40 mM sodium phosphate, pH 7.0. The sample was then fractionated through a size exclusion HPLC column equilibrated with 50 mM potassium phosphate, pH 6.0. Twenty-five 1 ml fractions were collected for a time of 25 minutes. The peak fractions were concentrated using the Speedvac. A small sample of PDP-MAb was run on SDS gel electrophoresis.
  • cross-linking substances may be used to chemically link the monoclonal antibody to the toxin in the methods described in the present invention.
  • suitable cross-linking agents include m-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS), N-succinimidyl-3-(2-pyridyldithio-)-propionate (SPDP), alpha-iminothiolane hydrochloride, methyl 3-mercaptopropionimidate, Succinimidyl 4-(N maleimidomethyl)cyclohexame-1-carboxylate (SMCC), 4-succinimidyloxycarbonyl-alpha-methyl-alpha-(2-pyridydithio)-toluene (SMPT), N-succinimidyl(4-iodoacetyl)aminobenzoate (SIAB) and sulfosuccinimidyl 4-(p-maleimidophen
  • toxins may be chemically linked to the monoclonal antibodies described herein.
  • suitable toxins include Pokeweed antiviral protein, gelonin, ricin, abrin, modeccin, dodecandrin, saporin, volkensin and vicumin.
  • an immunoconjugate of the present invention may be a fusion protein prepared by genetic engineering methods known to those in the art.
  • a fusion protein would contain the antigen recognition site of an antibody molecule and the cytotoxic moiety of a toxin.
  • the efficacy of the conjugates to specifically kill infected cells versus non-infected cells was demonstrated against a variety of cell lines in vitro.
  • Various concentrations of the immunotoxins were added to one or more cultures of the uninfected and correspondingly chronically-infected cells, the latter of which have recovered from any cytopathic effects of virus infection.
  • Cell viability and cell growth were monitored daily by propidium iodide exclusion and light scattering on an EPICS Profile flow cytometer.
  • cytotoxicity tests were carried out using disulfide linked immunoconjugates of pokeweed antiviral protein and gelonin, prepared as described above and tested against different cell lines and/or different HIV strains. Representative examples of these cytotoxicity tests are shown below.
  • FIG. 2 and TABLE I show the results of testing varying amounts of an anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin directed against an HIV strain (HIV-AC-1) infecting H9 cells with exposure of the cells to the immunotoxin for either 24 or 48 hours. After 24 hours of incubation, the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin killed about 65% of HIV-infected cells but only about 15% of uninfected (control) cells.
  • the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin killed about 95% of HIV-infected cells but only about 20% of uninfected (control) cells. Of note is the high specificity of the immunotoxin for HIV infected cells.
  • FIG. 3 and TABLE II shows the effects of the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin on the HIV cell line H-9 and HIV strain, PM-213 after exposure of the cells to the immunotoxin for either 24, 48 or 72 hours. After 72 hour incubation, the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin killed virtually 100% of HIV-infected cells but only about 20% of uninfected (control) cells.
  • the H-9 cell line used for these studies was derived from a single T- cell clone obtained from a specific HUT 78 cell line and selected for its high permissive growth with HIV-1. Further information about this cell line can be found in the National Institutes of Health AIDS Reference Research Reagent Catalog (January 1995).
  • the monoclonal antibody used in the preparation of the immunotoxin employed for the trials shown in FIGS. 2 and 3 was from Dr. M. G. Sarngadharan. Cells were grown and maintained in a carbon dioxide incubator at 37° C.
  • FIG. 4 shows a dose response relationship for cytotoxicity for the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin construct of the present invention after 1 day of incubation. Increasing cytotoxicity toward HIV infected cells was seen as the concentration of immunotoxin was increased. Similarly, FIG.
  • FIG. 5 illustrates a dose response relationship for cytotoxicity for the anti-reverse transcriptase monoclonal antibody-gelonin immunotoxin of the present invention. With both the PAP and gelonin containing immunotoxins selective killing of HIV infected cells was observed.
  • a third and more extensive series of trials was carried out using the same PAP and gelonin containing constructs and the same cytoxicity testing methods as used for the second set of trials.
  • the HIV strains HIV-IIIB and HIV-MN were employed in the H-9 cell line and incubations were carried out for 3 days.
  • the HIV-IIIB and MN virus lines are described in the National Institutes of Health AIDS Reference Research Reagent Catalog (January 1995).
  • FIG. 6 and TABLE III show the effect of the anti-reverse transcriptase monoclonal antibody-Pokeweed antiviral protein immunotoxin on H9 cells +HIV-IIIB.
  • the pokeweed antiviral protein immunotoxin produced about 77% cell death after 3 days. Approximately 90% of the cells were killed by the 10 nanogram/ml dose. Little toxicity was seen against uninfected cells.
  • H9 is the uninfected cell line.
  • the doses of the immunotoxin are given in ⁇ g/ml.
  • FIG. 7 and TABLE III show the effect of treating H9+MN cells for 3 days with the anti-reverse transcriptase monoclonal antibody-pokeweed antiviral protein immunotoxin of the present invention.
  • the PAP immunotoxin produced about 50% cell death after 3 days. Approximately 68% of the cells were killed by the 10 nanogram/ml dose at this time period. Again low toxicity against uninfected cells was seen.
  • FIG. 8 and TABLE IV illustrate the effect of the gelonin immunotoxin of the present invention on H9 cells plus HIV-IIIB over 3 days of incubation.
  • day 3 a dose of 1 nanogram/ml of the gelonin immunotoxin produced approximately 80% cell kill.
  • a 3.4 nanogram/ml dose of this immunotoxin resulted in approximately 90% cell death.
  • FIG. 9 and TABLE IV illustrate the effect of the gelonin immunotoxin of the present invention on H9 cells plus HIV-MN.
  • the gelonin immunotoxin produced approximately 80% cell kill after 3 days.
  • a 10 mg/ml dose of the gelonin immunotoxin resulted in approximately 93% cell death.
  • H9 is the uninfected cell line.
  • the doses of the immunotoxin are given in ⁇ g/ml.

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NZ306768A NZ306768A (en) 1995-04-14 1996-04-11 Anti-AIDS immunotoxins with a toxin conjugated to a monoclonal antibody
RU97118664/13A RU2191596C2 (ru) 1995-04-14 1996-04-11 Иммунотоксин против спида
IL11787096A IL117870A (en) 1995-04-14 1996-04-11 Anti-AIDS immunotoxins
EP96912684A EP0820470A4 (en) 1995-04-14 1996-04-11 NEW ANTI-AIDS IMMUNOTOXINS
AU55413/96A AU697418B2 (en) 1995-04-14 1996-04-11 Novel anti-aids immunotoxins
JP8531175A JPH11503730A (ja) 1995-04-14 1996-04-11 新規な抗エイズ免疫毒素
CA002216210A CA2216210A1 (en) 1995-04-14 1996-04-11 Novel anti-aids immunotoxins
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EP2568289A2 (en) 2011-09-12 2013-03-13 International AIDS Vaccine Initiative Immunoselection of recombinant vesicular stomatitis virus expressing hiv-1 proteins by broadly neutralizing antibodies
EP2586461A1 (en) 2011-10-27 2013-05-01 Christopher L. Parks Viral particles derived from an enveloped virus
EP2679596A1 (en) 2012-06-27 2014-01-01 Simon Hoffenberg HIV-1 env glycoprotein variant
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EP2873423A2 (en) 2013-10-07 2015-05-20 International Aids Vaccine Initiative Soluble hiv-1 envelope glycoprotein trimers
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Cited By (17)

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Publication number Priority date Publication date Assignee Title
US6627197B2 (en) 2000-02-16 2003-09-30 Bechtel Bwxt Idaho, Llc Selective destruction of cells infected with human immunodeficiency virus
US20040048784A1 (en) * 2000-02-16 2004-03-11 Keener William K. Selective destruction of cells infected with human immunodeficiency virus
US7018633B2 (en) 2000-02-16 2006-03-28 Battelle Energy Alliance, Llc Selective destruction of cells infected with human immunodeficiency virus
US7135173B2 (en) * 2000-07-13 2006-11-14 Idaho Research Foundation, Inc. Antiviral activity of Shiga toxin
US20030152593A1 (en) * 2000-07-13 2003-08-14 Idaho Research Foundation, Inc. Antiviral activity of shiga toxin
WO2003106479A2 (en) * 2002-06-17 2003-12-24 Parker Hughes Institute Pokeweed antiviral protein polypeptides with antiviral activity
WO2003106479A3 (en) * 2002-06-17 2005-06-30 Parker Hughes Inst ANTI-VIRAL PROTEIN POLYPEPTIDES WITH ANTIVIRAL ACTIVITY
US20060128941A1 (en) * 2002-06-17 2006-06-15 Uckun Faith M Pokeweed antiviral protein polypeptides with antiviral activity
EP3187585A1 (en) 2010-03-25 2017-07-05 Oregon Health&Science University Cmv glycoproteins and recombinant vectors
WO2012170765A2 (en) 2011-06-10 2012-12-13 Oregon Health & Science University Cmv glycoproteins and recombinant vectors
EP2568289A2 (en) 2011-09-12 2013-03-13 International AIDS Vaccine Initiative Immunoselection of recombinant vesicular stomatitis virus expressing hiv-1 proteins by broadly neutralizing antibodies
EP2586461A1 (en) 2011-10-27 2013-05-01 Christopher L. Parks Viral particles derived from an enveloped virus
EP2679596A1 (en) 2012-06-27 2014-01-01 Simon Hoffenberg HIV-1 env glycoprotein variant
EP2848937A1 (en) 2013-09-05 2015-03-18 International Aids Vaccine Initiative Methods of identifying novel HIV-1 immunogens
EP2873423A2 (en) 2013-10-07 2015-05-20 International Aids Vaccine Initiative Soluble hiv-1 envelope glycoprotein trimers
EP3069730A2 (en) 2015-03-20 2016-09-21 International Aids Vaccine Initiative Soluble hiv-1 envelope glycoprotein trimers
EP3072901A1 (en) 2015-03-23 2016-09-28 International Aids Vaccine Initiative Soluble hiv-1 envelope glycoprotein trimers

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